Bacteria take over robot's brain

A Virginia Tech scientist has designed bacteria that would be able to take over a robot’s ‘brain’, opening up the field of biochemical sensing between organism and non-organisms.

Warren Ruder, an assistant professor of biological systems engineering at Virginia Tech, used a mathematical model to demonstrate that bacteria can control the behaviour of an inanimate device like a robot.

Ruder said: “Basically we were trying to find out from the mathematical model if we could build a living microbiome on a non-living host and control the host through the microbiome.”

“We found that robots may indeed be able to have a working brain,” he said. Ruder is planning on building real-world robots that will have the ability to read bacterial gene expression levels in E. coli using miniature fluorescent microscopes – the robots will respond to bacteria he will engineer in his lab.

The study, inspired by the mating behaviour of fruit flies, was manipulated using bacteria, as well as mice that exhibited signs of lower stress when implanted with probiotics. It revealed unique decision-making behaviour by a bacteria-robot system by coupling and computationally simulating widely accepted equations that describe three distinct elements: engineered gene circuits in E. coli, microfluidic bioreactors and robot movement.

The bacteria in the mathematical experiment showcased their genetic circuitry by either turning green or red, according to what they ate. In the mathematical model, the robot was equipped with sensors and a miniature microscope to measure the colour of bacteria telling it where and how fast to go depending upon the pigment and intensity of colour.

The model also revealed higher order functions. In one instance, as the bacteria were directing the robot toward more food, the robot paused before quickly making its final approach – a classic predatory behaviour of higher order animals that stalk prey.

“We hope to help democratise the field of synthetic biology for students and researchers all over the world with this model," Ruder said.

“In the future, rudimentary robots and E. coli that are already commonly used separately in classrooms could be linked with this model to teach students from elementary school through PhD-level about bacterial relationships with other organisms.”

In agriculture, bacteria-robot model systems could enable studies that look into the interactions between soil bacteria and livestock, for example. In healthcare, further understanding of bacteria’s role in controlling gut physiology could lead to bacteria-based prescriptions to treat mental and physical illnesses.